Fuel for diesel engines



-20 the fuel by\ad Patented Jan. 21, 1936 UNITED STATES FUEL FOR DIESELENGINES Wilhelm Wilke,Mannheim,1Robert Stadler, Ziegelhausen, and FranzLappe, Ludwigsha'ien-onthe-Rhine, Germany, assignors to I. G.Farbenindustrie Aktiengesellschaft, Frankfort-onthe-Main; Germany NoDrawing.

Application November 29, 1932,

Serial No. 644,828. In- Germany December 5,

4 Claims. (Cl; 44-9) The present invention relates to improvements infuels for Diesel engines.

The application of the Diesel engine to rapidly running engines inparticular to vehicle motors,

5 has rendered it necessary to weaken the hard combustion stroke ofDiesel engines. For this purpose general attempts have been made toreduce the maximum pressure of combustion and to render the combustionsoft. The height of the maximum combustion pressure especially dependson the tendency of the fuel to ignite spontaneously. This tendencyvaries with the height of the compression pressure, the state of heat ofthe motor and the chemical nature of the fuel.

1 As it is not possible generally to reduce the maximum pressure ofcombustion by altering the conditions 0 the motor (namely thegeometrical measuremen s of themotor and the working conditions),attempts have been made to influence ditions. The incorporation of ethylnitrate, a'rnyl nitrite and similar substances is already known. 4 Wehave now found that the maximum combustion pressure of fuels in Dieselengines is re- 25 duced and the combustion influenced in a favorablemanner by incorporating with the fuels strongly unsaturated fluidaliphatic hydrocarbons containing more than two carbon atoms and morethan one multiple carbon bond, such as 30 hydrocarbons containing aplurality of triple linkages, as for example diacetylene,divinylacetylene,'and the like, or oleflnes having more than one doublelinkage, as for example allene, butadiene and the like. The liquidcondensate which 35 is obtained by cooling to low temperatures forexample to below 40 below zero 0. under ordinary or elevated pressure,the final gas obtained in the thermal or electrical production ofacetylene from gas containing hydrocarbons, as for 4.0 example in theelectric arc, may be directly employed as an addition. In addition ,todiacetylene, this condensate contains in particular allylene, allene andother strongly unsaturated substances partly liquid at normaltemperature 45 and even at higher temperatures which likewise influencethe combustion in the Diesel engine in the desired direction. Thehydrocarbons to be i added are gaseous or low boiling,-that is to say 7they-have a boiling point below 200 C., and in 50 the most cases below100 C.

The unsaturated hydrocarbons may be added While the addition effect whenemploying a gas oil. In the case of the gaseous additions, the upperlimit of the quantity of the additions is determined by the solubilityof the said gases in the fuels.

Every oil suitable as a fuel for Diesel engines 5 may be improved in thedescribed manner, for example tar oils, suitable fractions from naturalmineral oils or oils obtained by destructive hydrogenation. ofcarbonaceous materials.

It has been found that the fuels can be stored 1 for long periodswithout any loss of their excellent properties.

The following example will further illustrate the nature of thisinvention but the invention is notrestricted to this example.

' Example 5 parts by weight of .diacetylene are added to 100 parts byweight of mineral coal tar oil. When employing the fuel thus obtainedfor the operation of a Diesel engine the maximum pressure of thecombustion falls from 60 atmospheres (with mineral coal tar oil withoutaddition) to the neighborhood of the compression pressure of about 35atmospheres; the engine runs quite quietly.

The same effect is obtained by the addition of about 3 parts of theliquid condensate which is obtained by cooling to 80 below zero C. anelectric are gas containing acetylene (obtained by leading a mixture ofmethane and hydrogen through an electric arc) What we claim is:-

1. A fuel suitable for use in Diesel motors comprising a hydrocarbon oilheavier than naphtha containing an addition of a sufllcient amount, notexceeding 20%, of a fluid aliphatic hydrocarbon, containing mcre than 2carbon atoms and having more than one multiple carbon bend, to reducethe pressure at which spontaneous 40 combustion of the hydrocarbon oilwould normally occur.

2. A fuel suitable for use in Diesel motors comprising a hydrocarbon oilheavier than naphtha containing an addition of between 1 and 10% of afluid aliphatic hydrocarbon containing more than 2 carbon atoms and morethan one multiple' carbon bond.

3. Fuel according to claim 2, in which the hydrocarbonadded to thehydrocarbon oil is di- 0 acetylene.

4, A fuel according to claim 2, in which the hydrocarbon added to thehydrocarbon oil is the liquid condensate obtained by cooling to 80 belowzero C. aogas containing acetylene issuing from thetreatm .it ofhydrocarbon gases in the electric arc.

ROBERT STADLER.

FRANZ LAPPE.

